As the South Platte River enters western Nebraska near the northeastern corner of Colorado, it begins to parallel Interstate 80, one of America's major transcontinental highways.

The South Platte River crest has reached the city of North Platte. At 5 a.m. CDT Sunday, the river reached its highest level in recorded history at this location, rising to 14.03 feet and eclipsing the old record of 14.02 feet set June 3, 1935. It then crested at 1 a.m. CDT Monday at 14.36 feet. Flood stage is 13 feet.

The National Weather Service reported storm drains backing up into the city of North Platte, forcing some intersections to close. Residents spent part of their weekend sandbagging streets closest to the river.

On Friday morning, the river crested about a foot above its previous record crest from June 6, 1995 at Roscoe, Neb., about 45 miles west of North Platte. This crest was less than a foot below a level that would have flooded areas near Interstate 80.

The National Weather Service notes that the force of the floodwaters has led to scouring of the river banks and bottoms; in some cases this is causing the river level to drop while the amount of water in the river stays the same. The scouring action of the water is actually expanding the holding capacity of the river channel.

Over the next few days, the flood waters will slowly recede on the South Platte.

Where Does All This Water Go Next?

The South Platte River joins the North Platte River at the city of North Platte to become the Platte River, which then flows east through the rest of Nebraska. Among Nebraskans, the river is popularly described as "a mile wide and an inch deep," and indeed this moniker is often not much of an exaggeration.

Normally a shallow but very wide braided stream with numerous islands, the Platte is generally not navigable, although occasionally there is enough water for small recreational watercraft. The flood surge coming downstream will change that markedly, sending the river to potentially unprecedented levels (at least in modern recordkeeping) in western Nebraska.

At Brady, Neb., the Platte surged nearly 5 feet in 6 hours late Saturday as the leading edge of the flood surge arrived. During the same time, the amount of water flowing through the river at this point increased 77-fold, from 100 cubic feet per second to 7,700.

By 8 a.m. Sunday, the Brady gauge broke its 1973 record crest of 9.60 feet and has since risen much higher than expected, reaching 10.60 feet as of Monday morning, just over 3 feet above flood stage. Water is flowing over farm fields and rural roads in this area.

It remains to be seen how strong the flood crest will remain as it rolls through central and eastern parts of the Cornhusker State. Currently, the flood surge is expected to become less impactful as it rolls downriver, and flooding is not expected on the Platte east of Grand Island, Neb.

Eventually the Platte empties into the Missouri River south of Omaha, Neb. At that location, the water volume flowing down the Missouri River usually dwarfs that of the Platte. The Missouri River is well below flood stage now, so any flood surge on the Platte should be easily absorbed by the Missouri River and should not cause any problems downstream into the state of Missouri.

Interestingly, the water from this flood surge will eventually reach the Mississippi River and empty into the Gulf of Mexico. So the water from the Colorado deluge, which originated from water vapor transported north from the tropics, will eventually drain back into the tropics again.